Hello and thank you in advance as your suggestions and knowledge will be very appreciated.

Simple question:

I'm thinking about building my Dad and Sister both retaining walls. I've re-built two, one where the entire semi-circle had to be removed as the retaining blocks had shifted and became unlevel, the other another semi-circle on a hillside hugging a tree planted on the corner of a house.

The biggest question I have is of the process needed to build a wall where the landscape is about 3 foot approximately above grade of the sidewalk that runs directly along the property, and where I know that backfill will be required but lastly that the new wall will have the strength to enable a person to drive a riding lawn mower at or near the edge. My father has gotten older and just this last week he had to buy his first riding mower. Ain't life a ( ) he would say.

The relative information is that I'm in zone 5 Illinois and I know that soil freezing depths could have something to do with how deep and wide of a hole needs to be dug and how much depth of rock must be added to the hole, however I do not know if the rock is supposed to meet at the level of the sidewalk or if the blocks must be started below the sidewalk level. I also do not know if rebar or another method of stiffening must be taken into consideration.

I would plan to use simple ordinary retaining blocks that join up neatly and uniformly together. Suggestions as to weight or size/style of block if necessary, I'd also appreciate your input about as well. Again it needs to support a smaller than average, city riding-mower. This particular mower in fact is built to maneuver through gates, so you can see that I'm not talking about building the rock of gibraltor here.

And please advise me if there could be anything else I may not have asked about or that I am blindly assuming is some sort of norm.

Once again thank you.

Sincerely,

Dax